Flotation of sulphide minerals from sulphide bearing ore

ABSTRACT

A process for the recovery by flotation of sulphide minerals from ores whereby a pulp of the ground ore is conditioned in at least one agitation conditioning stage in the pH range of about 8.0 to 12.0 in the presence of a sulfhydryl anionic collector, after which the conditioned pulp is subjected to flotation to produce a concentrate high in the desired sulphide minerals recovery and a tailings impoverished in the desired sulphide minerals.

United States Patent Weston [54] FLOTATION 0F SULPHIDE MINERALS 2.693.877 107N754 Drake 11197164 FROM SULPHIDE BEARING ORE 2.716.600 8/1955 Frick 109. 166 X 3.750.154 (7/1956 Blake 109/167 X Inventor: David Weston. 34 Parkwood 2.767.842 10/1956 menu 20 mm Toronto, Canada 2.919.802 H1961) Drake 3097107 3.220.551 11/1905 Mo \cr.. 1091167 1 Notice: The portion of the term of 11118 3301790 3H9 fohn 3mm, X P SubSP-qufmt 1990! 3,329,266 7/1967 (tn 3097707 has been disclaimed. 3.386.572 611968 Cndncll 11197166 x 3 435.951 4/1969 CorhetL. 11197167 1 [973 3.450.257 67 1969 Cund :uws [:1] Appl NU 339,384 3.596.838 8/1971 Weston 111 9 166 X 3.667.691) (111972 Weston 11.19. 160 X Related U.S. Application Data 7 5 31 57mm wcsitm. 11m. um X 1631 ('ontinnntion-in-part of Sen INC. 267.205. June 38. OTHER PUBLIQATIONS I973. ahnndoned. Continuation-impart of Ser. N0. 1711.961. Jul 19. 1972. Pat. No. 3.735.931. Chem. Abst. 67. 1967. 1117;). commulflifln-in-pml of Theory of Flotation. Klnssen & Mokroisou. 1963. pp. 1972. abandoned. 393. 394.

g f, hif i l g PI'IIH(H' 1E.\mri1r1c/'Robert Hulper 41107710". A cm. 11' l'u-m De 11011 '1; O Brien 5m Field 01 Search 209/166. 167. 3. 4. 9 g p {561 References Cited 1571 ABSTR'K I UMTED S ES PATENTS A process for the recover h flotation of sulphide 1.619.791) 371917 Bragg. 309/166 m' 9 whcrcm d W! or 9 5" lbmwm SHQR Lems 1 v I t n log/I66 1S Conditioned in at least one agitation eonditionmg {9857513 131935 stronghum H log/I67 stage in the pH range Ofuhout 8.11m 11.11 In the presj s g t 77194 woodhouse 309 ence of a SL11111)'(11' \'1 anionic collector. utter which the 2.3 10.1-11. 371943 Keck 209/l66 conditioned pulp is subjected to flotation to produce 4 2.349.637 5/1944 Rucknardt 209/166 concentrate high in the desired sulphide minerals re 33997345 5/1946 Allen 399/107 covery and u tuilings impoverished in the desired sul 2.485.178 10 1949 Booth 209/166 phide minsmls 1.664.199 1/1954 Barker 109/167 1.682.716 771954 Nil] 209/166 91 Claims. 19 Drawing Figures DROCSS USWIG CONVENTIONAL FI CYIC lLllLl IGENT m 1607 home omcuv'tl 111/ uum TAM PM IIIIIG REIGEIYS COL kICYOR mum I003"!!! All) SIGNED! FLOTII'IOI sccnon OOLLECYOR LID FUOVNII min COIC 0mm: ma num" "'1 CLElNER YMLINQS TO LEICNING M041 CL! l-Illl FLO T I! CLllIll mun" F IIL TMLS I! BLED-Ill COQCUYIAYI FHIIL WOIIITIlYE OI AOOIT OIIL CLIAIEI 51'!" INN TIILINU! FLWIIO COUIYKI CUQREIT PROCESS USING CONVENTIONAL PRACTICE ALKALI AGENT 10 snmome cmcun TANK FOR COLLECTOR MIXING IM REAGENTS PULP @FROTHER l2 IPuLP ous'rm BUTORI ROUGHER mo scnveneen TH COLLECTOR AND FRO ER ammo" SECTION F I 1 ROUGHER mums OR ROUGHER CONCENTRATE SGAVENGER c NCENTRATE SGAVENGER mums FINAL TAILS 2/ i II 221/ THIGKENER v I 23 REGRIND cmcun'l COLLECTOR AND FROTHER m 1 CLEANER FLOAT I m1 CLEANER muuss N'l CLEANER CONCENTRATE TO LEAOHING PLANT OR 26 FINAL TAILS N'Z 25V CLEANER FLOAT N'2 CLEANER CONCENTRATE N'2 CLEANER TAILINGS FINAL CONCENTRATE OR ADDITIONAL CLEANER STEPS WITH TAILINGS FLOWING COUNTER CURRENT FIG 1 U.S. Patent N0v.l1,1975 Sheet2of 15 3,919,079

PROCESS USING INVENTION PRACTICE GRINDING CIRCUIT 2T1 ALKALI L AGENT 3 STEP AGITATOR )3? COLLECTOR? CONDITIONERS WITH usme FLOAT cELLs FOR HIGH ENERGY INPUT TO PULPAS AGITATION CONDITIONERS HIGH ENERGY INPUT DISPERSING/ To PULPL 28 I AGENT ERoTIIER- RESIDENCE TIME l-O To 20 IIINuTEs I coNDITIoN OR PuLi 3: AeITATIoN coNDITIoN DISTRIBUTOR wITI-I DISPERSING AGENT AND WITH OR WITHOUT ADDITIONAL ROUGHER AND scAvENeER COLLECTOR FLoTATIoN sEcTIoN l SCAVENGER coNcT, ROUGHER coNc'T- scAvENeER TAILINGS 7 FINN. TAILINGS "A" CIRCUIT I 37 ALKALI AGENT coNDITIoN AND COLLECTOR 38 on AsITATIoN coNDITIoN mm J ADDITION or DISPERSING AGENT? msPERsANT cmcu" AND ALKALI AGENT FOR cLosE 4.3

I PH CONTROL AND mm on CONDITION OR 31 wmIouT COLLECTOR AGITATION coNDITIoN .5 r I a CIRCUIT M1 2 CLEANER FLOAT I I N1 cLEANER TAILINes N 1 cLEANEn N'l CLEANER coNc T- TO FINAL TAILINGS on GONGENTRATE "a" CIRCUIT RETURN To N2 on N3 I 4/; STEP OF AG'MTOR coNDITIoN wITII [REDRIND cIRcuIT|is GONDITIONERS FOLLOWING ADDED DISPERS'NG AGENT GRINDING CIRCUIT. REAGENTS AND FLOWSHEET As "A" CIRCUIT N'Z cLEANER FLoAT N2 CLEANER coNcENTRATE FINAL coNcENTRATE on AoDITIoNAL CLEANING STEP FURTHER CONDITIONING AND M HIGHER PH IF PYRITE PRESENT FIG 2 U.S. Patent Nov. 11,1975 Sheet30f 15 3,919,079

PROCESS USING CONVENTIONAL PRACTICE ROUGHER CONGENTRATE OR SPECIFIC FLOAT CONCENTRATE FROM PRIMARY FLOAT CIRGUOT1/45 WITH POSSIBLY CYANIDE Tosnmome CIRCUIT OR aesnmo mu.

THICKENER 4/ 45 -g |ReeRmo ClRCUlT 4, 4-

P l I SPECIFIC FLOAT CONC'T.

an CLEANER FLOAT u 1 CLEANER TAILINGS N mu-zAuea CONCENTRATE TO LEAOHING PLANT on -cc1.|.EcTon FINAL TAlLs m 2 ;4q CLEANER FLOAT mo-olz-o lfifio m2 CLEANER TA 1 uses FINAL CONCENTRATE on ADDITIONAL CLEANER STEPS wnH TAILINGS FLOWING COU NTER CURRENT FIG 3 US. Patent Nov.

Sheet 4 of 15 PROCESS USING INVENTION PRACTICE FLOAT CIRCUIT 53' 7 men CONCENTRATION TIME -5 TO MINUTES CONDITION OR COLLECTOR IF NO CARRY OVER FROM ROUGI'IER HIGH ENERGY INPUT AGITATION CONDITION TO CLOSELY CONTROL PH N" 3 CLEANER TAILINGS N' 3 C LEANER CONCENTRATE FINAL CONCENTRATE FIG4 54 OPTIMUM RANGE uo-s-ue SPECIFIC FLOAT CONCENTRA'I'E 1 CLEANER FLOAT :56 u- 1 cum. N 19.5mm concT. mums TO VFINAL mums nEsRmo (noun L DISPERSANTPHS-S-IZ-G W IFLOVI m IF men as ''man: 5 PYRITE 2' coursu'r g cou'rem 2 F I DISPERSANT conomou on AGITATION -v couomon OR I ADDED PYRITE common FOR 0-510 IO mm. 591/ AGITATION 3 PH m To me OEPRESSANT IF covwmon uzczssmv um; TO omuun d '66 RANGE 9-5 TO :2-0 2 ma: OF couomoume 0-5 TO 3 MINUTES I 5 CLEMER 62 2| I W: CLEANER FLOAT 1 9 m2 cuzmsa couceu'rnne CLEANER TAILINGS conomon OR 3 7 I AGITATION couomou )6? I N 2 CLEANER CONCTI FOR 0.5 o 6 m5, QkFCP I pH \2-5 TO I2'6 63?, u-a cum. RS 'ZE FLOAT 3 CLEANER I FLOAT N 3 CLEANER TAILINGS 7/ L "'3 CLEANER CONCENTRATE FINAL CONCENTRATE US. Patent Nov. 11, 1975 Sheet 5 of 15 PROCESS USING CONVENTIONAL PRACTICE PRIMARY FLoAT men GRADE TAILS ROUGHER CONCENTRATE 7 CLASSIFIER s A N as 5 LI M E s DENSITY DENSITY 35 TO 457. souos 20TO30/. souos SANDS FLoAT 7 2/ SLIMES FLOAT COLLECTOR; on AND FROTHER ANo FROTHER TAILS GONCENTRATE TAILS CONCENTRATE FINAL cues FINAL TLGS R GRIND I 771/6 THICKENER I) I I V l N! 9 c LEANER FLoAT N ICLEANER TAILINGS o 1 CLEANER T0 LEACH PLANT on FINAL TAILS GONCEI'TRME N' 2 CLEANER 82 FLOAT FIG 5 N 2 CLEAN ER 283 US. Patent Nov. 11,1975 Sheet60f 15 3,919,079

PROCESS USING INVENTION PRACTICE PRIMARY FLOAT HIGH RA ER H R N NTRAT TAlLS 0LASSlFlER 72 84 5 AN 0 s s MES DENSH'Y 3510450,. DENSITY 20 TO 35% souos songs l smos FLOAT 87 :GLAEIOENi 01mg u u v u COLLECTOR 957/ "o m 20 MINUTES COLLECTOR FROTHER OPTIMUMPH ao.s- "-6 m r men y coucsmamou TAILS GONGENTRATE FlNAL mums {V sumzs FLOAT 88 FROTHER REGRIND 4- 4 cmcurr 7 r i z 4 conczmm'e TMLS CONDITION FINAL mums DlSPERSANT-- Gr 0Rc T o A non ONDI n COLLECTOR o-s TO 3 mus.

5 couamzo conccumne j 7 common on CLEANER FLOAT FOR 0-5 T0 3 MINS. MEDIUM conczmmmon L N'Z CLEANER SLlMES non 47 m3 CLEANER muues TO HEAD OF PRIMARY 98 FLOAT on To "-2 CLEANER m2 CLEANER;

sLmEs sums m2 CLEAN/ER sumzs FLOAT communal-: rm uses N" 3 CLEANER CONCENTRATE FINAL CONCENTRATE OR ADDITIONAL CONVENTQONAL CLEANER FLOAT FIG 6 CLEANER CIRCUIT SECTION US. Patent Nov. 11, 1975 PLANT F LOWSHEET LIME IGRINDING CIRCUIT Sheet 7 of 15 FINAL CO NCENTRATE /l/ RESIDENCE TIME COPPER MINE l-O mus. RE ga PU P SELECTIVE COLLECTOR I L P AG FROTHER PRIMARY ROUGHER PLUS MM SCAVENGER FLOATS FLOTATION CIRCUIT PH Km 0.2

Y SCAVENGER coNc'T. SCAVENGER TAILINGS FINAL TAILINGS o-ums Cu.

ROUGHER coucsmrmz f '1 k t w 'EW 151 CLEANER 'nuume's 1ST 01.5mm coucsumn: L PH |oo 2ND CLEANER TMLINGS I 2ND CLEANER CONCENTRATE cao I R E GRIND P404 I PHIO'S f'\ l wuo's [3RD CLEANER FLOAT was V 3RD CLEANER mums SELECTIVE 3RD CLEANER conceumn: PHKH, 4TH CLEANER FLOAT M I W 4TH CLEANER Tmuues I l l l U.S. Patent Nov.11,1975 Sheet8of 15 3,919,079

FLOWSHEET OF THE INVENTION APPLIED TO CLEANER CIRCUIT ONLY snmome cmcun |-Lms 407 NONI SELECTIVE uuvxme TANK MINERAL COLLECTOR RESIDENCE TIME 1'0 "INS. FOR REAGENTS 4- FROTHER P 2 WITH PELP 2708 ROUGHER PLUS PRIMARY A SCAVENGER nous l l gzng lgu IscAveNeER coucgmn:

SCAVENGER TAILINGS FINAL TAILINGS O'IIO'A CU- nouenea cgmcamamz I10 CONDITION H u-s Ercuanuzn FLOAT m "-5 I}!!! OISPERSANT SODIUM SILICATE I-OMINS. RES. TIME NON S ELEGTIVE' COLLECTOR \LST CLEANER TAILINGS J 1ST CLEANEEI CONCENTRATE [2N0 CLEANER FLOAT 1m "-1 |4HZ 2ND CLEANER 'rmunss I 2ND CLEANER CONCENTRATE/II3 m REGRIND a "-7 TO I2-5 NO N SELECTIVE COLLECTOR AGITATION common um:

IO MINS. PH 12-31012-5 fill/4 L r\ 3RD cum n TAILINGS 3RD CLEANER ooNc'T.

/I/I/6 Eta? yH |2.2 T0 I2-s 4TH CLEANER TAILINGS I FINAL CONCENTRATE CLEANER CIRCUIT SECTION US. Patent Nov. 11, 1975 Sheet 9 of 15 3,919,079

FLOWSHEET OF THE INVENTION APPLIED TO CLEANER CIRCUIT ONLY WITH COPPER MINERALS HEAVILY ACTIVATED H 504 6T0? LB/TON ENDFH e-s osusnv 31% souos ca 0 2-7 LBS/TON CQO 2-0 LBS/TON O'OSLBSITON FROIHER O F 250 END DENSITY Sl'l. SOLIDS NO REAiG ENTS GRINDING 4/ CIRCUIT I (I8 AGITATION CONDITIONING 3 AGITATORS HIGH SPEED AGITATION SGAVENGER concr.

SCAVENGER TAILINGS FINAL TAILINGS R OUG H ER CONCE NTRATE I TO C LEANER CIRCUIT IDENTICAI. TO CLEANER CIRCUIT SHOWN ON FIG 8 FINAL TAILINGS O'O48% C FINAL CONGENTRATE 28'4%C FIG 9 US Patent Nov. 11, 1975 Sheet 10 of 15 3,919,079

CONDITIONING TIME MINUTES ACID STAGE FIG IO 0 2 4 6 B IO CONDITIONING TIME MINUTES ALKALINE STAGE FIG 11 Sheet 11 of 15 mz i h. OF 06 m2; uozuemum F U.S. Patent Nov. 11, 1975 US. Patent N0v.11, 1975 Sheet 12 of 15 3,919,079

-RISER DUCT FIG. I4

I616? RISER DUCT II III/III! [III I I II IIIIII FIG. I5

US. Patent Nov. 11, 1975 Sheet 13 of 15 1e; 7 ALKALI A ENT NO AGENT on ACID AGENT A. 1 ADJUSTED PULP DENSITY les THICKENER 4 9 1/ I86 AGITATION VIOLENT '9' IL uFLow ALKALI AGENT\ mu. SOLUTION o FLOW F COLLECTOR OR WATER TO '92 MILL SOL'N. 209 AGITATION VIGOROUS AF FRo'rH"ER\:

'93 ADJUSTED PULP DENSITY 19+ xjzwx PULP DISTRIBUTOR I95 ROUGHER AND SCAVENGER FLOTATION SECTION 1% I977 M499 scAvENsER coNcr. ROUGHER couc'T. SCAVENGER TAILINGS FINAL TAILINGS FIRST CLEANER secnou ALTERNATELY TO TH'CKENER AND REGRIND DIRECTLY TO REGRIND FIRST CLEANER FIRST CLEANER TA I u NGS CONCENTRATE a, 05 206 T0 REGRIND 2ND CLEANER FLOAT FIG. I6

PULP DENSITY SOUDS u Tm mob

N Tu

nub

In woa rmm. UmD O2 FIGI7 U.S. Patent Nov. 11, 1975 Sheet 15 of 15 3,919,079

PREFERRED PULP FLOW DIAGRAMS OF THE INVENTION SUITABLY PREPARED PULP OF THE ORE 1 TO IOaINCLUSIVE Acm AGENT ADoEDAs LBS, PER TON DRE on T0 P H POINT DENSITY BOTO 50% 501.105

MIN-REG. R OF P- DRAWN MIN.REQ- P. OF T- MIN. TOTAL POWER DRAWN KW. HRS. PER TON 3, 4, 5,s,1,a, 10a

PH 6-0 To 10-5 OPTIMUM pH POINT P '20 0 I2-3 DENSITY 25 T0459. DENSITY 25 To 45% SOLIDS SOLIDS MIN. REQ. R- OF P. DRAWN MlN-REQ. R.o|=P. DRAWN MIN- REQ. P. OF T. 2/ MIN.REQ. P. OF T. MIN. TOTALPOWER 1/2 2 MIN- TOTAL PDWER DRAWN KW. HRS. DRAWN KW- HRS- PER ToN PER ToN OPTIMUM PH POINT DENSITY 25T0 45% SOLIDS 22 1 MN REQ- R,oFP. DRAWN mN. RED. P. OFT. mm. TOTAL PDWER DRAWN KW HRS.

PER ToN 3 TO 11a INCLUSIVE F LOTATION PH 8'0 -12-O DENSITY 20 T0407. SOLIDS VIGOROUS AGIT. MIN.REQ.PERIOD OONCEtdTRATE TAILINGS FIG I8 FLOTATION OF SULPHIDE MINERALS FROM SULPHIDE BEARING ORE This invention is a continuation in part of application Ser. No. 267,205, now abandoned filed June 28, 1972, Application Ser. No. 270,961, now US. Pat. No. 3,735,931, filed July 19, 1972 and Ser. No. 304,540, now abandoned, filed Nov. 7, 1972.

BACKGROUND OF THE INVENTION This invention relates to improvements in the flotation recovery of sulphide and a number of non-sulphide minerals from ores, particularly copper minerals, nickel minerals and molybdenum minerals, in which sulfhydryl anionic collectors are used as the collecting agent.

In conventional flotation practice as applied to the flotation of sulphide minerals from sulphide bearing ores, the largest tailings losses usually take place in the fines fractions, that is, the minus 325 mesh, or even finer, that is, the minus 20 micron size fraction, and in the coarsest fraction of the grind, which normally contains the highest percentage of middling particles.

My invention employs sulfhyoryl anionic collectors and, in probably its largest economic application, pertains to a comparatively large increase in recovery of sulphide minerals by being able to effectively recover the minerals values in these size fractions. The present invention is not generally dependent upon the particular collector employed, but is directed to the preparation of pulps for flotation recovery of at least the sulphide mineral values. Thus, where in the present application I use the expression sulfhydryl anionic collectors I intend the term to include any sulphur-connected anionic collector or combination of collectors which, by conventional testing procedures, has been selected for the particular flotation application.

The sulfliydryl anionic collectors are discussed and classified in Flotation, Second Edition, A. M. Gaudin, McGraw Book Company lnc., New York, 1957, pages 181-184.

The term Agitation Conditioning Circuit may consist of one but preferably a number of individual agitation conditioning units wherein the units are arranged in series and the pulp flows from one agitator to the next, and whatever number may follow. When I use the term Agitation Conditioning Stage it may mean a single unit or a multiplicity of agitators. An agitation conditioning circuit may have anywheres from one to three or more agitation conditioning stages in which the agitators are arranged in series. The distinguishing feature between each agitation conditioning stage is where I add an acid agent or an alkaline agent to change the pH range within the agitation conditioning circuit. For instance, if prior to my final heavy activation agitation conditioning stage in the pH range of about 8.0 to 12.01 prefer to use a preceeding acid conditioning stage where, following the grinding circuit, I add sulphuric acid to the pulp to lower the pH within the range of approximately 1.2 to 6.5, I would condition the pulp in normally a minimum of three agitators in series. In the No. l Agitator the pH of the pulp may be 1.2, while at the discharge of the pulp from the third agitator the pH may have risen to as high as 7.0. I would term this as the first agitation conditioning stage of the agitation conditioning circuit. The pulp will flow from Agitator No. 3 to No. 4 and this second agitation condi- 2 tioning stage could be two agitators, that is, No. 4 and No. 5. I now add lime or calcium hydroxide to Agitator No. 4 and raise the pH to an optimum point within the range of 8.0 to 12.0. This would be the beginning of the Agitation Conditioning Stage 2. ln Agitation Conditioner No. 4 in this example I also add a sulfhydryl anionic collector. At the beginning the pH in Tank 4 may be 10.5 and on the discharge from Tank 5 would have dropped to a pH of 10.0. The pulp from Tank 5 may now flow into three additional agitators in series, Tanks 6, 7, and 8. In Tank 6, which would be the beginning of the third agitation conditioning stage, I add further lime to raise the pH of the pulp to l 1.6. I may also add additional collector to this tank. By the time the pulp flows through Tanks 6, 7, and 8 the pH of the pulp at the discharge of Tank 8 may have dropped to, say, 1 1.2. This would be the end of Agitation Conditioning Stage 3. The valuable sulphide minerals, and possibly pyrite in the pulp discharging from Tank 8 are in the heavily activated form of my invention. 1 add a frother to Tank 8 and the pulp would flow to the primary flotation circuit. It would be noted that in this illustrated case where there is continuous agitation conditioning, the distinguishing feature of the agitation conditioning stages is the addition of an acid agent or an alkaline agent to change substantially the pH range within the individual agitation conditioning stages.

I may use a combination of agitation conditioning tanks and flotation cells in an agitation conditioning circuit. For instance, following Tank 8 where the pulp flows or is pumped to flotation cells I may add frother or collector to one or more flotation units with the air turned off and the cells acting as the final period of agitation conditioning prior to flotation.

Where I use a number of flotation cells in series as agitation conditioning tanks, the same differentiation applies.

The term Agitation Conditioning Step" refers to the specific agitator or flotation cell in the series wherein the first agitator the pulp enters in the agitation conditioning circuit is referred to as Number 1 step. Alternately it means a single agitator.

By Acid Agent is meant an agent selected from the group consisting of sulphuric acid, sulphurous acid, and sulphur dioxide, and is used to lower the pH in the alkaline pH range, or reduce the pH of the pulp to a desired point or range in the acid pH range of about 1.2 to 6.5.

By Sulphidizing Agent" is meant an agent selected from the group consisting of sodium hydrogen sulphide, sodium sulphide or polysulphide, calcium sulphide, and hydrogen sulphide, from the use of which in my circuit in their application to copper ores a copper sulphide film is thought to form on certain non-sulphide copper minerals, resulting in such minerals to be collector coated with sulfl'iydryl anionic collectors and subsequently recovered by flotation.

Where I refer to Sulphide Copper or Copper Sulphide" minerals I not only mean such minerals as Chalcocite and Covellite, but also the complex Copper Sulphide minerals such as Chalcopyrite, the Copper lron Sulphide, and the other complex copper sulphides that commonly occur in copper deposits.

Where I refer to Sulphide Nickel or Nickle Sulphide minerals, the main mineral is Pentlandite, the nickel iron sulphide, but may also include such nickel minerals as millerite, the nickel sulphide.

Where I refer to Sulphide Molybdenum" or Molybdenum Sulphide minerals, I am referring to Molyb- 3 denite.

Where I refer to Sulphide Lead or Lead Sulphide minerals, I am referring to Galena.

By Alkaline Agent is meant an agent selected from the group consisting of lime, calcium hydroxide, sodium carbonate and lime or calcium hydroxide in combination with sodium or potassium carbonate, sodium hydroxide and ammonium hydroxide, and is used for upward adjustment of the pH of the pulp.

By the expression Heavy Activation is meant a stage of activation in which at least the desired minerals are so heavily activated that surfaces of the sulphide minerals will take on and maintain a highly effective collector coating resulting in their floating in a much shorter time than in current conventional practice, and in addition, will not be depressed in the cleaner circuit wherein the pH may be appreciably higher than the pH used in the primary circuit, and appreciably higher than the accepted optimum pH for flotation of the desired recoverable minerals. Heavy activation does not preclude substantial activation and collection of minerals other than the valued sulphide minerals and the expression is used to distinguish from the present day conventional practice wherein the collection of the minerals is accomplished by stage addition prior to and during flotation of much smaller amounts of sulfhydryl anionic collector with a view, over the complete flotation cycle, to collecting more and more of the desired mineral in stages while ideally collecting none of the other minerals constituting the ore. The relatively high concentration of collector used at one or more points in my circuits is one of the features of the invention. For instance, where l heavily activate and efiectively coat sulphide copper minerals in one or more agitation conditioning stages between the grinding circuit and the primary flotation circuit l may use as much as three times the amount of collector at this point alone as would be used in the total flotation circuit in applying current conventional practice to the same ore. in obtaining the optimum results of my invention the total amount of collector used as compared to conventional practice varies from about the same amount to as much as four hundred percent more dependent on the characteristics of the individual ore comparison. This phenomenom is not understood. Where I use the description of sufficient concentration of collector" I mean that the amount of collector present at this stage in my circuit is in sufficient amount, in combination with other elements of my invention, to either produce or maintain the excellent floatability of the sulphide minerals which is a characteristic of my process.

When I use the term pounds per ton" of various reagents, this is pounds per ton of the total original feed," unless otherwise specified.

By Dispersing Agent" is intended to be meant an agent which is nondeleterious to the flotation of sulphide minerals in the teachings of my invention, and which tends to create conditions of dispersion within the pulp at the prevailing pH to effect depression of the non-sulphide waste host rock minerals in subsequent flotation stage or stages. Where I use a dispersing agent the physical and chemical actions or reactions that take place under conditions of my invention and with relatively high concentration of dispersant compared to prior conventional use, is not understood, particularly the indicated effect of the dispersant as a strong activator for the collection of the sulphide minerals.

In describing the practice of my invention, the term agitation conditioning as distinguished from conventional practice is important. In my prior pending application Ser. No. 270,961, I have described an agitation conditioning circuit prior to rougher flotation. in plant practice the agitators consisted of cylindrical tanks using an impellor type mechanism with either a single impellor, or two impellors mounted one below the other on a single shaft.

In mixing reagents with the pulp to procure collector coating of sulphide minerals conventional practice uses the lowest possible agitation speeds with the main objects being to keep the solids in the pulp in suspension and distribute the reagents throughout the pulp. To quote Taggert, Section 12, page 20: With fine pulps large tanks and slow agitation, as by slow sweeps, will serve, the principal consideration in this case being dispersion of the reagents."

With coarsely ground ores, due to the settling out characteristics of the coarse particles, small tanks are employed with more vigorous agitation to prevent the coarse particles from settling out.

By Vigorous Agitation I mean fast circulation of the pulp within the individual agitator using substantially higher power to the agitation mechanism or mechanisms than would be required to keep a finely ground product of the ore in suspension at a specific pulp density.

By Violent Agitation" I mean not only fast circulation of the pulp within the individual agitator, but usually using in excess of 200 percent higher power to the agitation mechanism than would be required to keep the ground product of the ore in suspension at a specific pulp density, and of sufficient violence to cause splashing of the pulp within the agitator and entrainment of air within the pulp.

In my co-pending US. application Ser. No. 304,540, and earlier applications Ser. Nos. 267,205 and 270,961 (that is now allowed), I did not fully appreciate the important significance of the type of agitation conditioning produced being the resultant of the necessity for high energy input to be imparted to the pulp by the agitation mechanisms in order to obtain the optimum results from my invention. In all cases this high energy input produces a vigorous agitation which varies in re lationship to the requisite amount of power required by the agitation mechanisms, to obtain the optimum metallurgical results of the invention. This requisite high energy input can be measured by the horsepower drawn by the motors driving the Agitation Conditioning mechanisms and converted to kilowatt-hours per ton of ore treated.

To achieve optimum results from my agitation conditioning circuits I prefer to use an agitator design described later in this patent application.

By Agitation Mechanism" 1 mean the impellor or rotor or a number of impellors and rotors attached to a revolving shaft and by their design combined with other features for agitation such as stators, their speed of rotation, and the tank design bring about the agitation conditions of the pulp.

A single agitator may be equipped with one or more agitation mechanisms attached to their individual shafts, or a number of agitation mechanisms.

Each agitation mechanism may be driven by its own motor and drive arrangement, or alternately, a single motor may drive two or more mechanisms through such an arrangement as V-belts and pulleys.

In the laboratory work wherein the metallurgy was optimized, 1 used a duplicate mechanism of conven tional flotation equipment, such as the Denver laboratory flotation cell in which the agitating mechanism consisted of a rotor and stator, and similarly, the Fagergren laboratory flotation cell which again consisted of a rotor and stator. In this research work I found the speed of the rotor was quite important for optimum metallurgy. In all cases in the laboratory research programme the speed of the rotors for optimum results had to be raised sufficiently high to produce vigorous agitation of the pulp.

In the earlier stages of the invention this factor of high energy input imparted to the solids in the pulp with the resultant comparatively high speed agitation was not fully appreciated until it had been checked out at a later date on a variety of sulphide-bearing ores.

It was noted that on some types of sulphide bearing ores in which the slimes content, after comminution, was comparatively low, recovery of the minus 200 mesh sized sulphide particles was little improved, or in fact, poorer in using a dispersing agent in an agitation conditioning circuit. This factor was noted in my earlier and pending patent applications. In working with these ores at a later date in establishing certain conditions in the pulp which are described in a number of examples, a surprising increase in recovery was obtained when the vigorousness of agitation was increased appreciably over that required to keep a finely ground pulp in suspension, and in the absence of a dispersant. Another surprising result was an increase in recovery of the coarse middling particles.

Where I add an alkali agent or acid agent to the conditioning circuit to raise or lower the pH, I prefer to use vigorous to violent agitation particularly for fast absorption of an acid agent. Pulp density is also a factor in obtaining optimum results and my agitation conditioning in the various stages is about to 50 percent solids, with my preferred range being 30 to 50 solids. I use the higher percent solids at the head of the agitation conditioning circuit, with the lowest at the end of the circuit.

To establish the optimum agitation conditioning in the laboratory following optimizing of the other features of my invention wherein I use one rotor speed of the agitation mechanism, 1 then increase the speed of the rotor in steps until there is no further drop in the flotation tailings loss. I also check a lower and, if necessary, a higher rotor speed. By this means I arrive at the optimum speed range of the rotor for each agitation conditioning stage. I follow the same procedure in plant practice, equipping the agitators with various types of means described later in this application to rapidly vary the speed of the agitation mechanisms. By interpolation correlated with experience from plant practice the power necessary to drive the agitation mechanisms can be estimated as to the minimum power required, and optimum power required range to obtain maximum recovery of the desired minerals.

In plant practice, all other factors being equal, the conditions of agitation within the parameters of the agitation mechanism design can be measured by the horsepower drawn by the motors driving the agitation mechanisms. The horsepower drawn, in turn will be a relative factor to the energy imparted to the pulp by the agitation mechanisms. Although the phenomenon of this feature of the invention is not fully understood, it is thought that this imparting of energy to the pulp and particularly the ground ore particles is a most important part of the invention.

A surprising feature of the invention is that each agitation conditioning stage requires a specific minimum period of time of agitation at a minimum speed of rotation of the agitation mechanism with the motor driving the agitation mechanism drawing a minimum horsepower. If the speed of rotation of the agitation mechanism is substantially increased over this amount, one would conclude that the time factor would be substantially reduced. This is not generally the case, which would indicate that not only is the sufficient energy imparted to the pulp to obtain maximum recovery of the desired minerals important, but also that this approximate level of energy must be imparted to the pulp over a sufficiently long period of time.

In using shaped blade-type impellors for the agitation conditioning, this type of impellor is lower speed and the power input, in addition to the speed, depends upon the design and size, together with the tank design. In the first large scale plant operation using my process, this type of impellor design was used in the agitation conditioning circuit, as shown at FIG. 13. The power drawn by the various agitator mechanisms exceeded 50 percent to as much as 200 percent over the manufacturers recommendation for agitation to keep the solids in suspension with a normal safety factor. The first two agitators in which violent agitation conditions were produced incorporated power input to the agitation mechanisms of approximately 400 percent over the agitation requirements to keep the solids in suspension. ln plant practice, in addition to the type of agitation conditions which I have described, it is obvious that flotation cells can be used for agitation conditioning circuits with the speed of the rotors adjusted to an optimum. In plant practice I prefer to use a minimum of two cells or two tanks in series in any one agitation conditioning stage. I consider three tanks or three cells optimum in allowing for short-circuiting of the pulp and wherein the minimum required period of residence time of the pulp for agitation conditioning has a normal safety factor. I have found that any reasonable excess time over the required minimum is not deleterious to the metallurgy in any of my alkaline agitation conditioning stages. However, insufficient time will not produce the optimum desired results of my invention. For this reason, in the practical application of my invention l prefer to use a large safety factor which each alkaline agitation conditioning stage ensuring that the pulp has a sufficiently long period of residence time in each agitation conditioning stage to produce the optimum desired results.

Conventional practice recognizes the importance of the time required for collector coating of the desired recoverable minerals. One of the major differences of my invention in this respect is that the optimum time in conventional practice to obtain the maximum recovery at an acceptable grade of concentrate can be critical. The reference to these effects is Handbook of Mineral Dressing by Arthur F. Taggert, 194-7 published by John Wiley & Sons Inc., New York, Section 12, page 19, to quote: On the contrary, conditioning time may be too long, resulting in deterioration of recovery and- /or grade of concentrate; for this reason, once the optimum time has been determined arrangements should be made to hold time as nearly as constant as possible." In many plants it is impossible to attain anywheres even near a constant time due to the large variation in ore 7 tonnage handled by the grinding circuit. With ore segregation in the bins and varying grindability of the ore, the tonnage from the grinding circuit may vary over a 24-hour period by as much as 40 percent.

In conventional practice for the flotation of sulphides such as copper sulphide minerals, this optimum time period for the collector coating of the minerals with sulfliydryl anionic collectors is of very short duration, normally involving only mixing of the collector with the pulp either with addition to the grinding circuit, to a mixing tank following the grinding cirucit, or as in one of the most modern plants simply to the pulp from the grinding circuit before distributing the pulp to the primary flotation circuit banks of cells.

ln the application of my invention in respect to the pulp from the grinding circuit 1 use an agitation conditioning circuit with preferably an excess of conditioning time over the minimum for optimum results. For instance, in Example Xlll the contact time of the collector with the pulp prior to flotation was 36 minutes and gave the lowest tailings loss of the various all-alkaline circuits used. Such a period of time, in this application to the circuit, is unheard of in conventional practice.

The minimum period of time for an agitation conditioning stage is important and may vary from about two to thirty minutes. In applying my invention to a pulp of the ore positioned in the flowsheet between the grinding circuit and primary flotation circuit, I use a minimum agitation conditioning time of about four minutes wherein the pulp density is in the range of about 25 to 50 percent solids.

Where I use an individual agitation conditioning stage on a flotation product to increase the activation of weakly activated minerals such as may be contained in a rougher concentrate, scavenger concentrate, or cleaner tailing the agitation conditioning time necessary may be less than four minutes, and at densities varying from l5 to 45 percent solids. [n plant practice the residence time of the pulp can be calculated from the tonnage treated and pulp density. The residence time in the various agitation conditioning stages described in this application ignore the short-circuiting factor and in plant practice should be taken into consideration.

In the preferred embodiment of my invention in treating ores in which the major part of. the values are in the form of sulphide copper minerals or sulphide molybdenum minerals, for optimum metallurgy the minimum agitation conditioning time is about 4 minutes using a minimum of two agitation conditioning steps. Where I use two alkaline agitation conditioning stages I prefer to use a minimum of four agitation conditioning steps.

Where sulphide nickel values are present in the pulp, for optimum metallurgy the minimum agitation conditioning time is about 8 minutes using a minimum of three agitation conditioning steps. In this application of my invention copper sulphate may be added to the grinding circuit during the preparation of the pulp.

Where weakly activated minerals show up in the various flotation circuits, such as a scavenger concentrate from the last float on the primary flotation circuit or theend float of the first cleaner circuit, a scavenger tailing or tailing from the first or other cleaners, part or all of such products may be beneficially returned to one or more agitation conditioning steps in the agitation conditioning circuit positioned in the plant flowsheet between the grinding circuit and the primary flotation 8 circuit. The optimum place of return of such products can usually be determined by closed circuit laboratory work.

The second and third difference from conventional practice are the total amount of power input to the agitation mechanisms together with the rate or variable rate of power input to the individual mechanisms over the residence time period of the pulp in an agitation conditioning circuit.

The power drawn by the agitation mechanisms, that is, the impellors or rotors including losses in efficiency of the motors and driving mechanism such as a speed reducer, converted to kilowatt hours per ton of ore treated per four minutes of residence time is a minimum of 0.12 kilowatt hours. For instance, if a plant was treating 400 tons of ore per hour through my conditioning circuit with eight minutes residence time, the total power drawn by the motors driving the agitation mechanisms of all the agitators would be a minimum of Where part or all of a flotation product such as a scavenger concentration from the primary circuit or from the first cleaner circuit, or part or all of any tailings from the various cleaner circuits are fed into an agitation conditioning circuit positioned in the flowsheet between the grinding circuit and the primary flotation circuit, the residence time of the new feed from the grinding circuit must still be maintained at the minimum time period of about 4.0 minutes.

The rate of power input to any one agitation mechanism is also important. It may vary within the circuit as shown in some of the illustrations, and the method of obtaining the optimum rate of power input is described in this application. If the rate of power input throughout the whole of the agitation conditioning circuit is too low a high tailings loss of the valued sulphide minerals ensues. If the rate of power input throughout the whole of the agitation conditioning circuit is appreciably too high, maximum recovery will not be obtained.

This latter condition would be impractical to practice as not only would there be a waste of power but the maintenance of the agitation mechanisms could become a major source of cost and lost operating time.

One of the most surprising features of this invention is, that to the inventors knowledge, for the first time in the flotation of sulphide minerals the power used to drive the agitation mechanisms in an agitation conditioning circuit to obtain heavy activation of the desired sulphide minerals can be treated in the same manner as a reagent. For instance, where, in conventional practice a sulphide collector such as potassium amyl xanthane is stage added prior to and during rougher flotation, minimum amounts are required to activate the desired minerals. if the total amount is less than the requisite minimum, recovery of the desired minerals will suffer, If an excess is used, undesired minerals may be activated. Further, if a maximum is exceeded, particulrly just prior to rough floation, the froth is flattened and recovery of the desired mineral seriously afiected within the normal rougher circuit floation time.

In obtaining heavy activation of the desired sulphide minerals in my agitation conditioning circuit, the power input impartted to the pulp through the agitation mechanisms can be interpreted as stage added over a mini- 

1. A PROCESS FOR THE RECOVERY BY FROTH FLOTATION OF MINERALS FROM ORES CONTAINING AT LEAST ONE SULPHIDE MINERAL AND WHEREIN SAID AT LEAST ONE SLPHIDE MINERA IS A MAJOR ECONOMIC COMPONENT OF THE ORE AND WHEREIN A PLUP OF THE ORE HAS BEEN PREPARED CONSISTING OF A PLUP DENSITY SELECTED FROM THE RANGE OF ABOUT 20 TO 60 PERCENT SOLIDS AND SAID OF SAID ORE HAVE BEEN GROUND TO FLOTATION FEED SIZE COMPRISING: SUBJECTING SAID PREPARED PULP OF THE ORE TO CONDITIONING IN AT LEAST ONE AGITATION CONDITIONING CIRCUIT CONSISTING OF AT LEAST ONE ALKALINE AGITATION CONDITIONING STAGE AND AT LEAST THREE AGITATION CONDITIONING STEPS WHEREIN IN SAID AT LEAST THREE ALKALINE AGITATION CONDITIONING STEPS THE CONDITIONING IS CARRIED OUT IN THE PRESENCE OF AN ALKALINE AGENT SELECTED FROM THE GROUP CONSISIING OF LIME OR CALCIUM HYDROXIDE, SDIUM HYDROXIDE, SODIUM CARBONATE, ND AMONIUM HYDROXID AND WHEREIN THE PH OF THE PULP IS AT AT LEAST ONE OPTIMUM PH POINT WIITHIN THE PH RANGE OF ABOUT 8.0 TO 12.0 AND WHEREIN AT LEAST THE FINAL AGITATION CONDITIONING STEP PRIOR TO FLOTATION A SUFFICIENT CONCENTRATION OF COLLECTOR SELECTED FROM THE GROUP OF SULFHYDRYL AMIONIC COLLECTORS IS PRESENT AND SAID CONCENTRATION OF COLLECTOR IS IN THE RAGE OF ABOUT 0.02 TO 0.40 POUNDS PER TON OF ORE AND WHEREIN SAID PULP IS AGITATION CONDITIONED WITH AGITATION CON-
 2. The process of claim 1 wherein said prepared pulp of the ore is the remaining pulp following one or more flotation stages.
 3. The process of claim 1 wherein said prepared pulp of the ore is the slimes product produced in a sands-slime
 4. The process of claim 1 wherein said agitation conditioning circuit contains at least three agitation conditioning steps and wherein in at least two of said steps said sufficient power consumption per ton of ore treated is employed to produce heavy agitation of at least the one said sulphide mineral to achieve high recovery of said at least one sulphide mineral in said at least one subsequent froth flotation stage.
 5. The process of claim 1 wherein there is a dispersing agent present in the pulp in at least the last agitation conditioning step prior to flotation.
 6. The process of claim 1 wherein said at least one agitation conditioning stage in the pH range of about 8.0 to 12.0 is preceeded by at least one agitation conditioning stage in the pH range of about 1.2 to 7.9.
 7. The process of claim 1 wherein said at least one agitation conditioning stage in the pH range of about 8.0 to 12.0 is preceeded by at least one agitation conditioning stage in the pH range of 12.0 to 12.3.
 8. The process of claim 1 wherein there are at least two agitation conditioning stages in the pH range of about 8.0 to 12.0.
 9. The process of claim 1 wherein said agitation conditioning steps are arranged in series.
 10. The process of claim 1 wherein there is a sulphidizing agent present in the pulp in at least the last agitation conditioning step prior to flotation and the sulphidizing agent has been selected from the group consisting of hydrogen sulphide, sodium sulphide, calcium sulphide, and sodium hydrogen sulphide.
 11. The process of claim 1 wherein in addition to treating said prepared pulp of the ore a scavenger flotation concentrate produced from said froth flotation is fed to at least one step of said agitation conditioning circuit.
 12. The process of claim 1 wherein in addition to treating said prepared pulp of the ore at least part or all of one or more cleaner tailings produced from said froth flotation is returned to at least one step of said agitation conditioning circuit.
 13. The process of claim 1 wherein in addition to treating said prepared pulp of the ore at least one flotation cleaner tailing produced from said froth flotation is subjected to agitation conditioning in at least one independent agitation conditioning step prior to being returned to at least one step in said agitation conditioning circuit.
 14. The process of claim 1 wherein in addition to treating said prepared pulp of the ore at least one flotation cleaner tailing produced from said froth flotation is subjected to agitation conditioning in at least one independent agitation conditioning step prior to being fed to a flotation stage.
 15. The process of claim 1 wherein said at least one agitation conditioning stage in the pH range of about 8.0 to 12.0 is preceeded by an acid conditioning stage wherein the pH of the pulp has been lowered by an acid agent selected from the group consisting of sulphuric acid, sulphurous acid, and sulphur dioxide to within the pH range of abOut 1.2 to 6.5.
 16. The process of claim 15 wherein said acid agent is sulphuric acid and is control added to the pulp of the ore on a pounds per ton of ore basis.
 17. The process of claim 15 wherein said acid agent is sulphuric acid and is control added to the pulp of the ore on a ''''pounds per ton or ore-density of the pulp'''' basis.
 18. The process of claim 15 wherein said acid agent is sulphuric acid and is control added to the pulp of the ore to maintain an optimum pH point.
 19. The process of claim 1 wherein said at least one alkaline agitation conditioning stage consists of at least two agitation conditioning steps and said power consumption of said agitation conditioning mechanisms is in range of about 0.17 to 0.53 kilowatt hours per ton of ore treated per 5 minutes residence time of the ore in the said at least one agitation conditioning stage.
 20. The process of claim 1 wherein said at least one alkaline agitation conditioning stage consists of at least two agitation conditioning steps and said power consumption of the agitation conditioning mechanisms is in the range of about 0.22 to 0.82 kilowatt hours per ton of ore treated per 8 minutes residence time of the ore in said at least one agitation conditioning stage.
 21. The process of claim 1 wherein said at least one alkaline agitation conditioning stage consists of at least three agitation conditioning steps and said power consumption of the agitation conditioning mechanisms is in the range of about 0.23 to 0.65 kilowatt hours per ton of ore treated per 6 minutes residence time of the ore in said at least one agitation conditioning stage.
 22. The process of claim 1 wherein said at least one alkaline agitation conditioning stage consists of at least three agitation conditioning steps and said power consumption of the agitation conditioning mechanisms is in the range of about 0.28 to 0.94 kilowatt hours per ton of ore treated per 9 minutes residence time of the ore in said at least one agitation conditioning stage.
 23. The process of claim 1 wherein said at least one alkaline agitation conditioning stage consists of at least four agitation conditioning steps and said power consumption of the agitation conditioning mechanisms is in the range of about 0.34 to 1.06 kilowatt hour per ton of ore treated per 10 minutes residence time of the ore in said at least one agitation conditioning stage.
 24. A process for the recovery by froth flotation of copper minerals from copper bearing ores containing at least one sulphide copper mineral and wherein said at least one sulphide copper mineral is a major economic component of the ore wherein a pulp of the ore has been prepared consisting of a pulp density selected from the range of about 20 to 60 percent solids and wherein said solids of said ore have been ground to flotation feed size comprising: subjecting said prepared pulp of the ore to conditioning in at least one agitation conditioning circuit consisting of at least one alkaline agitation conditioning stage and at least three agitation conditioning steps wherein in said at least three alkaline agitation conditioning steps the conditioning is carried out in the presence of an alkaline agent selected from the group consisting of lime or calcium hydroxide, sodium hydroxide, sodium carbonate and ammonium hydroxide and wherein the pH of the pulp is at at least one optimum pH point within the pH range of about 8.0 to 12.0 and wherein in at least the final agitation conditioning step prior to flotation a sufficient concentration of collector selected from the group of sulfhydryl anionic collectors is present and said concentration of collector is in the range of about 0.04 to 0.40 pounds per ton of ore and wherein said pulp is agitation conditioned with agitation conditioning mechanisms with sufficient power consumption per ton of ore treated said power consumption being in the range of about 0.12 to 0.40 kilowatt hours per ton of ore per 4.0 minutes residence time of the ore in said at least one agitation conditioning stage and for a sufficiently long period of time and wherein said period of time is in the range of about 4.0 to 30 minutes to produce heavy activation of said at least one copper mineral to achieve high recovery of said at least one copper mineral in at least one subsequent froth flotation stage subsequently in the presence of a suitable frother subjecting said agitation conditioned pulp to froth flotation to produce at least one flotation concentrate enriched in said at least one copper mineral and a tailings impoverished in said at least one copper mineral.
 25. The process of claim 24 wherein said prepared pulp of the ore is the remaining pulp following one or more flotation stages.
 26. The process of claim 24 wherein said prepared pulp of the ore is the slimes product produced in a sands-slime split of the ore.
 27. The process of claim 24 wherein said agitation conditioning circuit contains at least three agitation conditioning steps and wherein in at least two of said steps said sufficient power consumption per ton of ore treated is employed to produce heavy activation of said at least one copper mineral to achieve high recovery of said at least one copper mineral in said at least one subsequent froth flotation stage.
 28. The process of claim 24 wherein there is a dispersing agent present in the pulp in at least the last agitation conditioning step prior to flotation.
 29. The process of claim 24 wherein said at least one agitation conditioning stage in the pH range of about 8.0 to 12.0 is preceeded by at least one agitation conditioning stage in the pH range of about 1.2 to 7.9.
 30. The process of claim 24 wherein said at least one agitation conditioning stage in the pH range of about 8.0 to 12.0 is preceeded by at least one agitation conditioning stage in the pH range of 12.0 to 12.3.
 31. The process of claim 24 wherein there are at least two agitation conditioning stages in the pH range of about 8.0 to 12.0.
 32. The process of claim 24 wherein said agitation conditioning steps are arranged in series.
 33. The process of claim 24 wherein there is a sulphidizing agent present in the pulp in at least the last agitation conditioning step prior to the flotation and the sulphidizing agent is selected from the group consisting of hydrogen sulphide, sodium sulphide, calcium sulphide, and sodium hydrogen sulphide.
 34. The process of claim 24 wherein in addition to treating said prepared pulp of the ore, a scavenger flotation concentrate produced from said froth flotation is fed to at least one step of said agitation conditioning circuit.
 35. The process of claim 24 wherein in addition to treating said prepared pulp of the ore at least part or all of one or more cleaner tailings produced from said froth flotation is returned to at least one step of said agitation conditioning circuit.
 36. The process of claim 24 wherein in addition to treating said prepared pulp of the ore at least one flotation cleaner tailing produced from said froth flotation is subjected to agitation conditioning in at least one independent agitation conditioning step prior to being fed to a flotation stage.
 37. The process of claim 24 wherein at least one flotation cleaner tailing is subjected to agitation conditioning in at least one independent agitation conditioning step prior to being fed to a flotation stage.
 38. The process of claim 24 wherein said at least one agitation conditioning stage in the pH range of about 8.0 to 12.0 is preceeded by an acid conditioning stage wherein the pH of the pulp has been lowered by an acid agent selected from the group consisting of sulphuric acid, sulphurous acid, and sulphur dioxide to within the pH range of about 1.2 to 6.5.
 39. THe process of claim 37 wherein said acid agent is sulphuric acid and is control added to the pulp of the ore on a pounds per ton of ore basis.
 40. The process of claim 39 wherein said acid agent is sulphuric acid and is control added to the pulp of the ore on a ''''pounds per ton of ore-density of the pulp'''' basis.
 41. The process of claim 38 wherein said acid agent is sulphuric acid and is control added to the pulp of the ore to an optimum pH point of the pulp of the ore.
 42. The process of claim 24 wherein said at least one alkaline agitation conditioning stage consists of at least two agitation conditioning steps and said power consumption of the said agitation conditioning mechanisms is in range of about 0.17 to 0.53 kilowatt hours per ton of ore treated per 5 minutes residence time of the ore in said at least one agitation conditioning stage.
 43. The process of claim 24 wherein said at least one alkaline agitation conditioning stage consists of at least two agitation conditioning steps and said power consumption of the agitation conditioning mechanisms is in the range of about 0.22 to 0.82 kilowatt hours per ton of ore treated per 8 minutes residence time of the ore in said at least one agitation conditioning stage.
 44. The process of claim 24 wherein said at least one alkaline agitation conditioning stage consists of at least three agitation conditioning steps and said power consumption of the agitation conditioning mechanisms is in the range of about 0.23 to 0.65 kilowatt hours per ton of ore treated per 6 minutes residence time of the ore in said at least one agitation conditioning stage.
 45. The process of claim 24 wherein said at least one alkaline agitation conditioning conditioning stage consists of at least three agitation conditioning steps and said power consumption of the agitation mechanisms is in the range of about 0.28 to 0.94 kilowatt hours per ton of ore treated per 9 minutes residence time of the ore in said at least one agitation conditioning stage.
 46. The process of claim 24 wherein said at least one alkaline agitation conditioning stage consists of at least four agitation conditioning steps and said power consumption of the agitation conditioning mechanisms is in the range of about 0.34 to 1.06 kilowatt hours per ton of ore treated per 10 minutes residence time of the ore in said at least one agitation conditioning stage.
 47. The process of claim 24 wherein said at least one alkaline agitation conditioning stage consists of at least two agitation conditioning steps and said total power consumption of said agitation conditioning mechanisms is in the range of 0.24 to 1.5 kilowatt hours per ton of ore treated and the residence time of the ore in said at least one agitation conditioning stage is in the range of about 8.0 to 20 minutes.
 48. The process of claim 24 wherein said collector is an alkali metal xanthate and said sufficient concentration of collector is a minimum of about 0.10 lbs. per ton of ore treated.
 49. The process of claim 24 wherein said collector is selected from the group consisting of thiols, thiocarbonates, monosubstituted thioureas, and thiophosphates and said sufficient concentration of collector is a minimum of 0.03 lbs. per ton of ore treated.
 50. The process of claim 24 wherein said collector is a combination of alkali metal xanthate and collector selected from the group consisting of thiols, thiocarbonates, monosubstituted thioureas, and thiophosphates and said sufficient concentration of collector is a minimum of 0.05 lbs. per ton of ore treated.
 51. A process for the recovery by froth flotation of nickel minerals from nickel bearing ores containing at least one sulphide nickel mineral and wherein said at least one sulphide nickel mineral is a major economic component of the ore and wherein a pulp of the ore has been prepared consisting of a pulp density selected From the range of about 20 to 60 percent solids and said solids of said ore have been ground to flotation feed size comprising: subjecting said prepared pulp of the ore to conditioning in at least one agitation conditioning circuit consisting of at least one alkaline agitation conditioning stage and at least three agitation conditioning steps wherein in said at least one alkaline agitation conditioning stage the conditioning is carried out in the presence of an alkaline agent selected from the group consisting of lime or calcium hydroxide, sodium carbonate, sodium hydroxide, and ammonium hydroxide and wherein the pH of the pulp is at at least one optimum pH point within the pH range of about 8.0 to 12.0 and wherein in at least the final agitation conditioning step prior to flotation a sufficient concentration of collector selected from the group of sulfhydryl anionic collectors is present and said concentration of collector is in the range of about 0.03 to 0.40 pounds per ton of ore and wherein said pulp is agitation conditioned with agitation conditioning mechanisms with sufficient power consumption per ton of ore treated said power consumption being in the range of about 0.12 to 0.40 kilowatt hours per ton of ore per 4.0 minutes residence time of the ore in said at least one agitation conditioning stage and for a sufficiently long period of time and wherein said period of time is in the range of about 4.0 to 40 minutes to produce heavy activation of said at least one sulphide nickel mineral to achieve high recovery of said at least one nickel mineral in at least one subsequent froth flotation stage: subsequently in the presence of a suitable frother subjecting said agitation conditioned pulp to froth flotation to produce at least one flotation concentrate enriched in said at least one sulphide nickel mineral and a tailings impoverished in said at least one sulphide nickel mineral.
 52. The process of claim 51 wherein said prepared pulp of the ore is the remaining pulp following one or more flotation stages.
 53. The process of claim 51 wherein said agitation conditioning circuit contains at least three agitation conditioning steps and wherein in at least two of said steps said sufficient power consumption per ton of ore treated is employed to produce heavy activation of at least the one said sulphide nickel mineral to achieve high recovery of said at least one sulphide nickel mineral in at least one subsequent froth flotation stage.
 54. The process of claim 51 wherein said sufficiently long period of time to produce heavy activation of said at least one sulphide nickel mineral to achieve high recovery of said at least one sulphide nickel mineral in at least one subsequent froth flotation stage is a minimum period of eight minutes.
 55. The process of claim 51 wherein there is a dispersing agent present in the pulp in at least the last agitation conditioning step prior to flotation.
 56. The process of claim 51 wherein said at least one agitation conditioning stage in the pH range of about 8.0 to 12.0 is preceeded by at least one agitation conditioning stage in the pH range of about 1.2 to 7.9.
 57. The process of claim 51 wherein there are at least two agitation conditioning stages in the pH range of about 8.0 to 12.0.
 58. The process of claim 51 wherein said agitation conditioning steps are arranged in series.
 59. The process of claim 51 wherein in addition to treating said prepared pulp of the ore a scavenger flotation concentrate produced from said froth flotation is fed to at least one step of said agitation conditioning circuit.
 60. The process of claim 51 wherein in addition to treating the prepared pulp of the ore at least part or all of one or more cleaner tailings produced from said froth flotation is returned to at least one step of said agitation conditioning circuit.
 61. The process of claim 51 wherein in additiOn to treating said prepared pulp of the ore at least one flotation cleaner tailing produced from said froth flotation is subjected to agitation conditioning in at least one independent agitation conditioning step prior to being returned to at least one step in said agitation conditioning circuit.
 62. The process of claim 51 wherein in addition to treating said prepared pulp of the ore at least one flotation cleaner tailing produced from said froth flotation is subjected to agitation conditioning in at least one independent agitation conditioning step prior to being fed to a flotation stage.
 63. The process of claim 51 wherein said prepared pulp of the ore contains copper sulphate.
 64. The process of claim 51 wherein copper sulphate is present in said prepared pulp of the ore prior is at least the last agitation conditioning step prior to flotation.
 65. The process of claim 51 wherein said at least one agitation conditioning stage in the pH range of about 8.0 to 12.0 is preceeded by an acid conditioning stage wherein the pH of the pulp has been lowered by an acid agent selected from the group consisting of sulphuric acid, sulphurous acid, and sulphur dioxide to within the pH range of about 1.2 to 6.5.
 66. The process of claim 65 wherein said acid agent is sulphuric acid and is control added to the pulp of the ore on a pounds per ton of ore basis.
 67. The process of claim 65 wherein said acid agent is sulphuric acid and is control added to the pulp of the ore on a ''''pounds per ton or ore-density of the pulp'''' basis.
 68. The process of claim 65 wherein said acid agent is sulphuric acid and is control added to the pulp of the ore to an optimum pH point of the pulp of the ore.
 69. The process of claim 51 wherein said at least one alkaline agitation conditioning stage consists of at least two agitation conditioning steps and said power consumption of said agitation conditioning mechanisms is in the range of about 0.17 to 0.53 kilowatt hours per ton of ore treated per 5 minutes residence time of the ore in said at least one agitation conditioning stage.
 70. The process of claim 51 wherein said at least one alkaline agitation conditioning stage consists of at least two agitation conditioning steps and said power consumption of the agitation conditioning mechanisms is in the range of about 0.22 to 0.82 kilowatt hours per ton of ore treated per 8 minutes residence time of the ore in said at least one agitation conditioning stage.
 71. The process of claim 51 wherein said at least one alkaline agitation conditioning stage consists of at least three agitation conditioning steps and the said power consumption of the agitation conditioning mechanisms is in the range of about 0.23 to 0.65 kilowatt hours per ton of ore treated per 6 minutes residence time of the ore in said at least one agitation conditioning stage.
 72. The process of claim 51 wherein said at least one alkaline agitation conditioning stage consists of at least three agitation conditioning steps and said power consumption of the agitation conditioning mechanisms is in the range of about 0.28 to 0.94 kilowatt hours per ton of ore treated per 9 minutes residence time of the ore in said at least one agitation conditioning stage.
 73. The process of claim 51 wherein said at least one alkaline agitation conditioning stage consists of at least four agitation conditioning steps and said power consumption of the agitation conditioning mechanisms is in the range of about 0.34 to 1.06 kilowatt hours per ton of ore treated per 10 minutes residence time of the ore in said at least one agitation conditioning stage.
 74. The process of claim 51 wherein said at least one alkaline agitation conditioning stage consists of at least two agitation conditioning steps and said total power consumption of said agitation conditioning mechanisms is in the range of 0.48 to 3.0 Kilowatt hours per ton of ore treated and the residence time of the ore in said at least one agitation conditioning stage is in the range of about 16 to 40 minutes.
 75. A process for the recovery by froth flotation of molybdenum minerals from molybdenum bearing ores containing at least one sulphide molybdenum mineral and wherein said at least one molybdenum mineral is a major economic component of the ore and wherein a pulp of the ore has been prepared consisting of a pulp density selected from the range of about 20 to 60 percent solids and said solids of said ore have been ground to flotation feed size comprising: subjecting said prepared pulp of the ore to conditioning in at least one alkaline agitation conditioning circuit consisting of at least one alkaline agitation conditioning stage and of at least three agitation conditioning steps wherein in said at least one alkaline agitation conditioning stage the conditioning is carried out in the presence of an alkaline agent selected from the group consisting of lime or calcium hydroxide, sodium carbonate, sodium hydroxide, and ammonium hydroxide and wherein the pH of the pulp is at at least one optimum pH point within the pH range of about 8.0 to 12.0 and wherein in at least the final agitation conditioning step prior to flotation a sufficient concentration of collector selected from the group consisting of sulfhydryl anionic collectors and fuel oil is present and said sufficient concentration of sulfhydryl anionic collectors is in the range of about 0.02 to 0.30 pounds per ton of ore and wherein said pulp is agitation conditioned with agitation conditioning mechanisms with sufficient power consumption per ton of ore treated said power consumption being in the range of about 0.12 to 0.30 kilowatt hours per ton of ore per 4.0 minutes residence time of the ore in said at least one agitation conditioning stage and for a sufficiently long period of time and wherein said period of time is in the range of about 4.0 to 20 minutes to produce heavy activation of said at least one sulphide molybdenum mineral to achieve high recovery of said at least one molybdenum mineral in at least one subsequent froth flotation stage: subsequently in the presence of a suitable frother subjecting said agitation conditioned pulp to froth flotation to produce at least one flotation concentrate enriched in said at least one sulphide molybdenum mineral and a tailing impoverished in said at least one sulphide molybdenum mineral.
 76. The process of claim 75 wherein said prepared pulp of the ore is the remaining pulp following one or more flotation stages.
 77. The process of claim 75 wherein there is a dispersing agent present in the pulp in at least the last agitation conditioning step prior to flotation.
 78. The process of claim 75 wherein said at least one agitation conditioning stage in the pH range of about 8.0 to 12.0 is preceeded by at least one agitation conditioning stage in the pH range of about 1.2 to 7.9.
 79. The process of claim 75 wherein said at least one agitation conditioning stage in the pH range of about 8.0 to 12.0 is preceeded by at least one agitation conditioning stage in the pH range of 12.0 to 12.3.
 80. The process of claim 75 wherein there are at least two agitation conditioning stages in the pH range of about 8.0 to 12.0.
 81. The process of claim 75 wherein said agitation conditioning steps are arranged in series.
 82. The process of claim 75 wherein in addition to treating said prepared pulp of the ore a scavenger flotation concentrate produced from said froth flotation is fed to at least one step of said agitation conditioning stage.
 83. The process of claim 75 wherein in addition to treating said prepared pulp of the ore at least part or all of one or more cleaner tailings produced from said froth flotation is returned to at least one step of said agitation conditioning circuit.
 84. THe process of claim 75 wherein in addition to treating said prepared pulp of the ore at least one flotation cleaner tailing produced from said froth flotation is subjected to agitation conditioning in at least one independent agitation conditioning step prior to being returned to at least one step in said agitation conditioning circuit.
 85. The process of claim 75 wherein in addition to treating said prepared pulp of the ore at least one flotation cleaner tailing produced from said froth flotation is subjected to agitation conditioning in at least one independent agitation conditioning step prior to being fed to a flotation stage.
 86. The process of claim 75 wherein said selected collector is a combination of a sulfhydryl anionic collector and a fuel oil.
 87. The process of claim 75 wherein said selected collector is fuel oil.
 88. The process of claim 75 wherein said at least one agitation conditioning stage in the pH range of about 8.0 to 12.0 is preceeded by an acid conditioning stage wherein the pH of the pulp has been lowered by an acid agent selected from the group consisting of sulphuric acid, sulphurous acid, and sulphur dioxide to within the pH range of about 1.2 to 6.5.
 89. The process of claim 88 wherein said acid agent is sulphuric acid and is control added to the pulp of the ore on a pounds per ton of ore basis.
 90. The process of claim 88 wherein said acid agent is sulphuric acid and is control added to the pulp of the ore on a ''''pounds per ton of ore-density of the pulp'''' basis.
 91. The process of claim 88 wherein said acid agent is sulphuric acid and is control added to the pulp of the ore to an optimum pH point of the pulp of the ore. 